Ovarian Eggs Research Articles

Optimization of Estrogenic Activities of Kebar Grassextract (Biophytum Petersianum) on White Female Mice (Mus musculus)

Menopause occurs caused bythe decline of estrogen hormone due to the depletion of the ovarian egg. As estrogen levels decrease, the risk of osteoporosis, bone fractures, heart disease and even cancer increase. The kebar grass (Biophytum petersianum), which has long been used as atraditional fertility medicine by Papuans, is suspected to have anestrogenic activity. The purpose of this study was to determine the estrogenic activity of kebar grass extract on female mice (Musmusculus). Five experimental female mice groups were used in this study. Each group consisted of 5 mice.The negative control group was administered with aquadest; the positive control was administered withesthero conjugated estrogen 0.625 mg; the first group (P1) was administered with 3%kebargrass extract; the (P2) group was administered with 5% kebar grass extract and the (P3) was administered with 10% kebar grass extract. The experiment was carried out for 7days. The results of the study showed that the kebar grass extract has an estrogenic effects on female mice include to shorten the estrous cycle, prolong the estrous phase, improving the vascularity of ovary and uterus, and increase the weight of ovary and uterus. The highest estrogenic activity was reached when the mice was administered with 10% kebar grass extract..

Potential fecundity, larval development, and survival of two invasive species of <i>Arhopalus</i> (Coleoptera: Cerambycidae) coexisting in southern South America

Biological invasions are one of the main threats to forest health. Although Arhopalus rusticus and Arhopalus syriacus (Cerambycidae) are alien species in South America, the ecology of these invasive species is not well studied. Here, we examined the effect of the female size on potential fecundity, size and number of mature eggs in ovaries, in both insect species. We also compared egg morphometric characteristics, larval measurements, larval development and survival between these two species. We found a positive relationship between the female size and the number of eggs in their ovaries but no relationship between the female size and egg morphometric characteristics in each of these two species. The females of A. rusticus were significantly larger and had bigger eggs than those of A. syriacus, but no significant difference was observed in the number of eggs between them. Larval body length and head capsule exuviae width were larger in A. rusticus than in A. syriacus. Arhopalus rusticus had the highest larval survival rate, but A. syriacus had the shortest larval period. Thus, female and egg size, as well as larval size and survivorship are competitive advantages to A. rusticus. However, A. syriacus has a similar number of eggs to A. rusticus and faster larval development; these could be key features to explain the coexistence of these two species.

Development and reproduction of the parasitic wasp Allotropa subclavata (Hymenoptera: Platygastridae) on the Japanese mealybug Planococcus kraunhiae (Hemiptera: Pseudococcidae)

Allotropa subclavata Muesebeck (Hymenoptera: Platygasteridae) is one of the most effective natural enemies of the Japanese mealybug Planococcus kraunhiae (Kuwana) (Hemiptera: Pseudococcidae), a serious pest in Japanese orchards. We examined the developmental and reproductive traits including host deprivation effect on oviposition of A. subclavata to evaluate its potential as a biological control agent for P. kraunhiae. The developmental zero and effective accumulative temperature of A. subclavata females and males reared on second-instar nymphs, a suitable host stage for this parasitoid, were 12.3 °C and 514.3 degree days and 12.8 °C and 432.8 degree days, respectively. The longevity of A. subclavata maintained with honey was longer than that of those maintained with water or no feeding. The average numbers of mature eggs in ovaries of the 0- and 30-day-old A. subclavata females were 301.1 and 290.4, respectively, and were not significantly different. Offspring production of 30-day-old A. subclavata females was approximately 80% that of 0-day-old female parasitoids. On average, 50% of all eggs were laid within 24 h of the start of oviposition. The intrinsic rate of increase at 25 °C was 0.115, which is considered to be approximate to that of the host, P. kraunhiae.

Comparative study of biology on ground beetles (Coleoptera: Carabidae) - flight ability, feeding habits and fecundity

We studied flight ability, feeding habits and fecundity in carabids. Based on these traits, we investigated characteristics of five species of Harpalus, Synuchus and Carabus as bioindicators of changing environments. Three species of Harpalus, H. griseus, H. eous and H. tridens, showed different degrees of flight ability. We examined the morphology and the length of hind wings, and also investigated by dissection the phenology of flight muscles. The ratio of hind wing to body length (HWBL) was 0.93 in H. tridens, 0.99 in H. eous and 1.02 in H. griseus. The aerial catches ratio to total catches (aerial / aerial+ pitfall traps) of H. tridens was lower (16%) than the other two (72, 76%), and the proportion of individuals with flight muscles of H. tridens (29%) was lower than the other two (71, 77%), indicating H. tridens has lowest flight ability. All three species exhibited flight muscle polymorphism. The hind wings of Synuchus cycloderus were mono-morphic macropterous with 0.75 (HWBL). However, no individuals were caught by aerial traps, and none possessed the flight muscles, indicating this species does not fly. The hind wings of Carabus procerulus were mono-morphic stick-shaped brachyptery without the flight muscle. Flight is important trait for food searching and dispersal. Gut dissection revealed that three Harpalus species depended mainly on seeds and partly on arthropods. The fact that animal fragments were found more frequently in the guts of H. tridens than the other two indicated a close relationship between flight ability and diet. Through gut dissection, we found S. cycloderus was a generalist predator. It preys not only on larvae but also adults of small arthropods including collembola. The food remains of guts of C. procerulus consisted of amorphous fluid, and cuticles were hardly detected. It suggested that the inside of prey was exclusively consumed by extra-oral digestion rather than chewing. Fecundity was assessed by gonad dissection through the number of ovarian eggs and their size. S. cycloderus had many eggs with small size, by contrast C. procerulus and three Harpalus species had few-large eggs. Many studies have shown that ground beetles responded differently to vegetation disturbances. We interpreted these results from their ecological traits. Our previous study of the vegetation disturbance effects on ground beetles demonstrated that C. procerulus declined in number was accompanied with decline in body size. Food shortage induced the reduction in both number and body size of C. procerulus. On the other hand, the number of S. cycloderus significantly increased. Although some of their prey were reduced, as generalist predators, they alternatively consumed other prey that has increased greatly in number. The trait of S. cycloderus with many eggs has also great potential for population explosion. The numbers of H. griseus and H. eous were not affected by the disturbance, while H. tridens decreased. Shortage of prey organisms caused negative effects on H. tridens compared to H. griseus and H. eous which depend more on seeds. We have been studying ground beetles in Japan, and already have some basic knowledge, such as hind wings, flight ability, feeding habits, reproductive phenology and seasonal activity for 78 key species. Ground beetles are excellent bioindicators. Our bottom up approach by the dissection of ground beetles collected periodically through the year would be essential when we have to face with extreme conditions, such as global warning.

Effect of Erythritol onDrosophila suzukii(Diptera: Drosophilidae) in the Presence of Naturally-Occurring Sugar Sources, and on the Survival ofApis mellifera(Hymenoptera: Apidae)

Previous studies have demonstrated various combinations of non-nutritive erythritol and sucrose having detrimental effects on Drosophila suzukii (Matsumura). Fly mortality is likely caused by 1) starvation from feeding on non-metabolizable erythritol; and 2) physiological imbalance with abnormally high osmotic pressure in the hemolymph. While erythritol kills D. suzukii in controlled environments, flies in the field can access naturally-occurring sugar sources. We evaluated fly mortality in the presence or absence of wounded fruits, and an erythritol mixture of 2.0 M erythritol:0.5 M sucrose (E+S), or erythritol- and sucrose-only controls. When provided E+S, survival was consistently lower than sucrose controls with/out wounded fruit, suggesting that this mixture still has a detrimental effect in the presence of competing sugar sources. Our second study examined the effects of diet on fecundity and egg load of female D. suzukii. Females laid fewer eggs on blueberries when fed E+S or erythritol-only than sucrose. Unexpectedly, females fed E+S had more ovarial eggs than sucrose-fed females, suggesting that erythritol might inhibit D. suzukii laying eggs. Lastly, we evaluated honey bee survivorship by enclosing bees with one of four diets in a cage. The erythritol mixture had no discernible impact on adult survivorship during 7 d.

Fecundity and Embryonic Development of Spiny Dogfish in the Northwest Atlantic Ocean

AbstractWe investigated the fecundity and embryonic development of Spiny Dogfish Squalus acanthias (68.8–88.4 cm TL; n = 49) caught in the northwest Atlantic Ocean off Long Island, New York, between October 2014 and January 2015. Ovarian fecundity ranged from 0 to 6 eggs, whereas uterine fecundity ranged from 0 to 7 embryos. The average ovarian fecundity and uterine fecundity were equal at 4.1, and fecundity increased with maternal body length. All ovarian eggs and embryos in an individual female were at the same stage of development. Ovarian eggs (n = 200) ranged from 1.4 to 4.9 cm in diameter and weighed between 1.3 and 39 g. Embryos (n = 200) ranged from 8.6 to 27.5 cm TL and weighed between 2 and 74 g. The sex ratio of the embryos (female : male) was 1.17:1.00; however, within individual females, one sex dominated over the other. The development of ovarian eggs was concurrent with embryo development. The data collected in this study can be used in future stock assessments for the northwest Atlantic Spiny Dogfish population.

Decadal Assessment of Polycyclic Aromatic Hydrocarbons in Mesopelagic Fishes from the Gulf of Mexico Reveals Exposure to Oil-Derived Sources.

This study characterizes a decadal assessment of polycyclic aromatic hydrocarbons (PAHs) in the muscle tissues of mesopelagic fish species as indicators of the environmental health of the Gulf of Mexico (GoM) deep-pelagic ecosystem. Mesopelagic fishes were collected prior to the Deepwater Horizon (DWH) oil spill (2007), immediately post-spill (2010), 1 year after the spill (2011), and 5-6 years post-spill (2015-2016) to assess if the mesopelagic ecosystem was exposed to, and retained, PAH compounds from the DWH spill. Results indicated that a 7- to 10-fold increase in PAHs in fish muscle tissues occurred in 2010-2011 (4972 ± 1477 ng/g) compared to 2007 (630 ± 236 ng/g). In 2015-2016, PAH concentrations decreased close to the levels measured in 2007 samples (827 ± 138 ng/g); however, the composition of PAHs still resembles a petrogenic source similar to samples collected in 2010-2011. PAH composition in muscle samples indicated that natural sources (e.g., Mississippi River and natural seeps) or spatial variability within the GoM do not explain the temporal variability of PAHs observed from 2007 to 2016. Furthermore, analysis of different fish tissues indicated the dietary intake and maternal transfer of PAHs as the primary mechanisms for bioaccumulation in 2015-2016, explaining the elevated levels and composition of PAHs in ovarian eggs.

Effects of low-temperature summer nights on adults of Monochamus alternatus (Coleoptera: Cerambycidae)

ABSTRACTTo clarify the factors determining the northern distribution limit of Monochamus alternatus Hope, which vectors the pinewood nematode, we examined our hypothesis that “low-temperature summer nights in cool regions affect the survival, maturation feeding, and ovary development of M. alternatus, and determine its distribution limit.” We measured summer air temperatures in three pine forest stands in northern Japan. Based on the results, we examined the effects of low nighttime temperatures on survival, maturation feeding, and ovary development in the laboratory. Low nighttime temperatures had little effect on the survival and the total amount of maturation feeding of M. alternatus adults. A daytime temperature of 25°C and nighttime temperature of 15°C did not affect ovary development. In contrast, 25°C in the daytime and 10°C in the nighttime delayed ovary development and reduced the number of mature eggs, but some ovary eggs were able to mature under this condition. We concluded that the effect of low-temperature summer nights on ovary development alone could not explain the northern distribution limit of M. alternatus.

Two Fungicides Alter Reproduction of the Small Brown Planthopper Laodelphax striatellus by Influencing Gene and Protein Expression

Aside from their intended actions, fungicides can drive pest insect outbreaks due to virtually continuous use and pest evolution. Small brown planthopper (SBPH), Laodelphax striatellus, outbreaks occurred recently in many provinces in China, with devastating rice losses. Because exposure to the fungicide jinggangmycin (JGM) increased reproduction of the brown plant hopper, Nilaparvata lugens, via its influence on fatty acid synthase, we posed the hypothesis that JGM and carbendazim (CBM) influence SBPH reproduction via their influence on enzymes involved in other aspects of lipid metabolism. Exposure to the fungicide CBM stimulated SBPH reproduction (egg-laying up by 78%) and to another fungicide, JGM, led to decreased egg-laying (down by 47.3%). These inverse effects are mediated by down-regulated expression of l-3-hydroxyacyl-coenzyme A dehydrogenase (LCHAD) in JGM-treated females and up-regulated expression of hydroxysteroid dehydrogenase-like protein 2-like (HSD) in CBM-treated females. RNAi knockdown of, separately, LCHAD and HSD led to reduced egg-laying (down by 52% for dsLCHAD and by 73% for dsHSD). dsLCHAD, dsHSD, and JGM treatments also led to severely reduced ovarian development in experimental SBPH, with shorted and thinned valvula and lack of egg cells in ovaries. Valvula of CBM-treated females enlarged, with banana-shaped eggs in ovaries. These data strongly support our hypothesis.

Gametogenesis, sex ratio and energy metabolism in Ostrea angasi: implications for the reproductive strategy of spermcasting marine bivalves

Spermcasting is an unusual reproductive strategy in some aquatic species in which functional males release gametes to fertilize eggs inside the body cavity of functional females. As some spermcasting bivalves have high ecological and economical importance, the understanding of their reproductive strategy is crucial for aquaculture, fisheries and conservation. This study investigates gametogenesis, sex ratio and energy metabolism in Ostrea angasi to elucidate the reproductive strategy of spermcasting bivalves. Gonad histology indicated asynchronous development of spermatozeugmata, but synchronous development of oocytes within an individual. The hermaphroditic individuals released spermatozeugmata before egg ovulation. The population of 2–3 year old oysters comprised 46.7% hermaphrodites and showed a highly skewed male to female ratio of 7:1. This species primarily metabolized glycogen as the energy source for gametogenesis, with an overlapping period of energy storage and utilization. This pattern of gametogenesis suggests multiple production of spermatozeugmata in a reproductive season in male and hermaphroditic oysters, but a single episode of egg ovulation in female and hermaphroditic oysters. The dynamics of energy metabolism indicate that O. angasi follows a strategy for energy metabolism that is intermediate between those of conservative and opportunistic species. This study suggests that unsynchronized gamete development, skewed sex ratio and intermediate energy metabolism are adaptive strategies in the reproduction of spermcasting bivalve species.

Life History of a Unique Asian Plethodontid Salamander, Karsenia koreana.

Using preserved specimens, we studied the basic life history of the topotypic population of the unique Asian plethodontid salamander, Karsenia koreana. Of 51 individuals examined, 11 males and 13 females were judged as mature from the development of gonads. The ovarian eggs were large (diameter 3.7-4.8 mm) and yellow to orange in color, and the clutch size was about 8-10. These values approximate those of actually spawned eggs recently reported. Skeletochronological analyses revealed the average age of males (5.3 years) to be lower than females (7.3 years). The age at maturity and maximum observed longevity were four and nine years in males and five and 10 years in females, respectively. In the growth curves estimated by a von Bertalanffy growth model, the growth coefficient and asymptotic SVL did not differ between the sexes, although males (40.6 mm) were smaller than females (45.3 mm) in the average snout-vent length. The time and place of courtship behavior, oval development, hatching, and especially, whether the species shows aquatic larval stage or direct development, are important topics to be resolved in future.

The influence of dietary antioxidant on ovarian eggs and levels of vitamin E, C, A, astaxanthin, β-carotene and oxidative stres in tissues of Astacus leptodactylus (Eschscholtz) during reproduction

The experiment was conducted to determine the most effective antioxidant (among the vitamin E (VE), vitamin C (VC), vitamin A (VA), astaxanthine (AX), β-carotene (βC)) on the ovarian egg number and size, level of VE, VC, VA, AX, βC and oxidative stress (as malondialdehyde (MDA)) in the hepatopancreas, ovarian, gills and muscle tissue during ovarian development of Astacus leptodactylus. One control (C) and five experimental diets (EE, EC, EA, EAX and EβC) were prepared. The EE, EC, EA, EAX and EβC groups were formed by added 150 mg kg-1 VE, 200 mg kg-1 VC, 240 mg kg-1 VA, 200 mg kg-1 AX and 200 mg kg-1 βC to diet C, respectively. At the end of the experiment found that the dietary antioxidants increased ovarian egg number and size and reduced the level of MDA in the tissues. Ovarian egg number and size were highest in the EE and EAX diet groups in the comparison to control (p<0.001). The level of MDA in the tissues was lowest in the EAX diet group in the comparison to control (p<0.001). The highest levels of VE, VC, VA, AX and βC were found in the hepatopancreas and ovarian compared with muscle and gills. The highest level of MDA also was determined in the ovarian according to other tissues. In conclusion, the VE and AX in broodstock diets were the most effective antioxidants on the ovarian egg number and size of A. leptodactylus.

Ovarian maturity, egg development, and offspring generation of the deep-water shrimp Plesionika edwardsii (Decapoda, Pandalidae) from three isolated populations in the eastern North Atlantic

ABSTRACTOvarian maturity, egg development and brood size were analysed for three isolated populations (Madeira, the Canary Islands and Cape Verde Islands) of Plesionika edwardsii (Decapoda, Pandalidae) in the eastern Atlantic. Multiple colour patterns were observed at the same ovarian maturity stage, which was verified histologically, invalidating the extensive use of ovarian colour as a maturity stage criterion. The physiological size at sexual maturity, based on the maturity of the ovaries, was higher in Madeira (carapace length of 19.73 mm) and decreased to the Cape Verdes (16.39 mm). Synchronic ovarian maturation was observed during the embryo incubation process, and ovigerous females bearing embryos at the final stage of development were found throughout the year. Females are multiple spawners during the reproductive season, after which the reproductive process ends and a rest period begins. The absence of females larger than the size at sexual maturity with ovaries in Stage 1, the incubation of embryos in the final developmental stages, suggests that the resting period begins with a process that reabsorbs the energy located in the ovaries and that the resting period occurs asynchronously in females in each of the studied populations. Embryo size was independent of female body size in the three populations studied, but increased with the developmental stage. A power equation was used to describe the relationship between brood size and female body size in the three areas studied. The mean number of external Stage I embryos carried by females decreased from Madeira (n = 7868) to the Cape Verdes (n = 3781), where less energy, in terms of the number of embryos and the size of the eggs, was invested in reproduction. Although female size decreases from north to south, the egg number was higher in Madeira than in the Cape Verdes for the same size range.

Field notes on the reproduction of the Cheat Mountain Salamander (Plethodon nettingi).

In 1989, the U.S. Fish and Wildlife Service designated the Cheat MountainSalamander as a federally threatened species. I have collected data on this speciesover a 39-year period spanning from 1976 through 2015. Sexually mature malesdisplay two secondary sexual characteristics, squared snouts and swollen cloacae.Squared snouts are usually first observed in late July and early August. Cloacae startto swell in late August and early September. By mid-September, both characteristicsare obvious and these traits continue to be observable until late May of the ensuingyear. Mature ovarian eggs are visible through the body wall of sexually maturefemales in late August or early September. Gravid females, i.e., those with matureovarian eggs, are easily distinguished from nongravid females in September, October, and November or until they submerge into their winter subterraneous refugia. Gravid females continue to be easily identified the ensuing spring after emergence from winter refugia to early June. The latest date I have found gravid females in the spring/summer is June 10. By early June, gravid females have deposited their eggs and are tending them in nests under rocks, logs, or in logs. I have observed nests with eggs and tending females from May 15 to July 26. I have found neonates in nests with females in September, indicating that eggs hatch in September.

Incubation Time Required for Hatching, and Ecological Characteristics of the Mode of Life Related with Total Numbers of the Suckers on Each Short Arm of the Hatched Juvenile Larvae of Octopus ocellatus (Cephallopoda: Octopodidae), in Western Korea

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at 20.9-21.5℃ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at 11.0-20.4℃. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

Transmission of symbiotic fungus with a nonsocial leaf-rolling weevil

Transmission modes of symbionts with fungus-growing insects are closely related to the stability of symbioses. As compare to social fungus-farming insects, transmission modes of nonsocial fungus-farming insects need to be further investigated. Euops chinensis, a nonsocial leaf-rolling weevil, harbors a symbiotic fungus Penicillium herquei in the specialized mycangium. Previous works have indicated that P. herquei is cultivated to host plants by females during oviposition process, however, it is still unclear when (before or after oviposition) and how P. herquei is transmitted. In this study, we observed fungal cultivating behaviors and adult bodies by scanning electron microscopy (SEM), and compared isolation rates of P. herquei on ovary eggs, newly oviposited eggs, cradle leaves (leaf pieces cut before rolling cradles), cradles, and female mycangia. Fungal isolates were identified by internal transcribed spacers (ITS) and cytochrome oxidase I (COI) genes. We found the female's serrated tarsi and comb-like setae on the abdomen were specialized structures for fungal transmission. Newly oviposited eggs showed 81.11% frequency of fungal symbionts, but ovary eggs did not show any growth of fungal symbionts. Isolation rates of P. herquei on cradle leaves, mycangia and cradles were 76.67%, 77.71% and 87.72%, respectively. Analyses of ITS and COI genes showed that isolated fungal strains belong to the same species. We concluded that P. herquei was transmitted before oviposition, and the female's tarsi are newly found specialized structures for fungal transmission. This study elucidates the cultivar transmission mode with fungus-farming attelabid weevils, and might be useful to study of other fungiculture mutualisms.

Follicle cell trypsin-like protease HrOvochymase: Its cDNA cloning, localization, and involvement in the late stage of oogenesis in the ascidian Halocynthia roretzi.

We previously reported that the sperm trypsin-like protease HrAcrosin and its precursor HrProacrosin participate in fertilization of the ascidian Halocynthia roretzi. The HrProacrosin gene is annotated in the H. roretzi genome database as Harore.CG.MTP2014.S89.g15383; our previously reported sequence of HrProacrosin gene appeared to include four nucleotides inserted near the 3'-end of HrProacrosin, resulting in a frame-shift mutation and a premature termination codon. The gene architecture of HrProacrosin and Harore.CG.MTP2014.S89.g15383 resembles that of Xenopus laevis ovochymase-1/OVCH1 and ovochymase-2/OVCH2, which encode egg extracellular polyproteases. Considering these new observations, we evaluated the cDNA cloning, expression, localization, and function of Harore.CG.MTP2014.S89.g15383, herein designated as HrOvochymase/HrOVCH. We found that HrOVCH cDNA consists of a single open reading frame of 1,575 amino acids, containing a signal peptide, three trypsin-like protease domains, and six CUB domains. HrOVCH was transcribed by the testis and ovary, but the majority of protein exists in ovarian follicle cells surrounding eggs. An anti-HrOVCH antibody inhibited elevation of the vitelline coat at a late stage of oogenesis, during the period when self-sterility is acquired. As trypsin inhibitors are reported to block the acquisition of self-sterility during oogenesis, whereas trypsin induces the acquisition of self-sterility and elevation of the vitelline coat in defolliculated ovarian eggs, we propose that HrOVCH may play a role in the acquisition of self-sterility by late-stage H. roretzi oocytes.

Body size, reproduction and feeding ecology of Pleurodema diplolister (Amphibia: Anura: Leiuperidae) from Caatinga, Pernambuco state, Northeastern Brazil

We present data about body size, sexual dimorphism, reproductive traits and diet ecology of Pleurodoma diplolister. This species is sexually dimorphic with females larger than males, corroborating others Leiuperidae species. The number of eggs varied from 62 to 1241 and we found a positive relationship between SVL of females and number of mature ovarian eggs but there is no relationship between SVL and volume of eggs. The diet of P. diplolister was composed by 11 categories of which Formicidae, Coleoptera and Orthopterans were the most important items and showed generalist and oportunistic predator habits. Data presented here should be considered in the development of future conservation strategies of anurans from Caatinga biome and other semiarid/arid environments.

Plasticity in fecundity highlights the females’ importance in the spiny-cheek crayfish invasion mechanism

Invasion is one of the most consequential phenomena affecting the distribution of native species. Few in number of species, European crayfish are losing the competition with introduced North American crayfish. The spiny-cheek crayfish, Orconectes limosus, is an outstanding example, successfully competing against the native narrow-clawed crayfish, Astacus leptodactylus. For four years, we collected data regarding crayfish occurrences, their relative abundance, and the structure of populations in the ongoing colonisation process of O. limosus in the lower Danube. The mature females of both invasive and indigenous crayfish species were analysed with respect to biometry and production of oocytes in relation to the dynamics of invasion. The interspecific comparisons showed no significant differences regarding body size, with an average of approximately 102mm total length and 31g wet weight for both species. However, the fecundity of the indigenous species was found to be constant throughout the investigated area, whereas the number of eggs produced by the invasive females was significantly increased at the active front of the invasion. The maximum number of ovarian eggs found was 887 and 1156 in the indigenous species and the invasive species, respectively. We propose the scenario that the invasive species, which carries the deadly crayfish plague, creates an ecological advantage by reducing the populations of indigenous crayfish. Subsequently, the invasive females opportunistically use the available resources to enhance their fecundity, resulting in the acute growth of populations. However, the long-term competitiveness and colonisation success of O. limosus still remain in question.

Gametogenesis, Mating Behaviour and Spawning of Octopus ocellatus (Cephalopoda: Octopodidae) in Western Korea

Gametogenesis, mating behaviour and spawning of Octopus ocellatus were investigated by histological study. This species is dioecious, and showed a protandry phenomenon. Ooogenesis (in females) and spermatogenesis (in males) can be classified into 3 stages, respectively. O. ocellatus copulates in one of two ways: a male may leap upon a female, mounting her mantle, or a male may sit near the female and extend the hectocotylized third right arm toward her. Spawning occurred between April and June in females, and between March and May in males of O. ocellatus. The spawning period was once a year and the peak took place between May and June. A number of flatened follicle cells, which were attached to an oocyte, were involved in vitellogenesis in the cytoplasm of the vitellogenic oocyte (maturing oocyte), and formation of chorion membrane (secondary egg membrane) of the ovarian eggs. Fecundity per female closely related to GSI was 294-660 eggs (average, 429 eggs). The diameters of the ovarian eggs surrounded by chorion membrane were approximately in the range of 10.10-2.50 ㎜. Each ovarian egg laid by a female was connected to an egg string. Each egg string was 1-5.5 ㎝ (average 3.6 ㎝). The total number of eggs laid by a female of this species ranged 218-314, the egg sizes were independent to the size of female adult. this species has a life mode showing some special reproductive characteristics of an annual semelparity as shown in Octopodidae species because we have never seen a female spawning a second time.